“Fantastic man I came to know well,” Stallone wrote. “He was the real Apollo Creed!”

Sylvester also posted a throwback snap to his very first meeting with Muhammad, admitting the champ gave him “a slight tap in the stomach” when they met. Stallone described the famed boxer as “an amazing humanitarian.”

Sylvester Stallone had a special friendship with the late Great One, but when he first met him, he was practically starstruck. One of their most famous early interactions occurred when Ali surprised Sylvester Stallone at the 1977 Academy Awards. As Sylvester Stallone was getting ready to present an Oscar, Muhammad Ali snuck up on stage behind him and told him he was the real Apollo Creed and accused Sly of “stealing his script” for the Rocky movies.

“I’m the real Apollo Creed! You stole my script!” Muhammad teased.

The two then sparred on stage before going in for a friendly bear hug. Sylvester Stallone later got emotional as he told the audience he felt honored to be standing beside the boxing great.

“I may not win anything here tonight in the form of an Oscar, but I really feel it’s an amazing privilege to be standing next to a 100 percent certified legend and it’s something I want to treasure for the rest of my life,” Stallone said.

Sylvester Stallone has long touted Ali as the greatest fighter who ever lived. Last year, Sylvester told Interview magazine that his idol Muhammad Ali was “just incredible.” Stallone also joked that if people ever mistakenly ever thought Rocky Balboa beat Muhammad Ali, he would “set them straight.”

Sylvester Stallone’s first Rocky movie was reportedly inspired by Ali’s 1975 fight against underdog Chuck Wepner. The then-unknown boxer was a 40-1 underdog who went 15 rounds against the champ before being defeated. Sylvester Stallone won an Oscar for his story of Rocky, an underdog who fights reigning champ Apollo Creed, the following year, and according to ESPN, Wepner later sued Stallone for “cashing in on his life story and never sharing a dime with ‘the real Rocky.’ ” Sylvester Stallone settled with Wepner for an undisclosed amount, but the movie franchise went on and on, and so did Stallone’s friendship with the real-life legend that inspired his movie foe.

As for Carl Weathers, the man who played Ali’s alter ego in the film franchise, he told the Hollywood Reporter that the real-life champ always wanted to fight him when he ran into him in public.

“One time in Beverly Hills, I was sitting outside a restaurant and Ali was coming down the street and had a group of people around him… and they look over where I’m sitting and Ali goes ‘Apollo Creed!’ ” Weathers said. “Then all of a sudden, there is Muhammad and I standing on the sidewalk throwing punches. It was so bizarre. It was all just in good fun, of course. Last time I saw him was in New York in a hotel lobby, and it has to be 11:30 at night, and he makes me get up to make sure I know he can still whip me. And there we were on our toes, bouncing, and it was just so bizarre but such fun.”